Cookies

Cookies are a technology which can be easily and simply used by a Webmaster to achieve a great many very useful tasks when creating websites. Although cookies are well known to users, many people are not really sure what they are used for, and a large amount of webmasters don't realise the possibilities open to them when they use cookies.
Read more in this Cookies Tutorial

This site has a wealth of tutorials on a range of webmastery-type subjects. Well worth a look if you haven't already done so ...